In many cases, a related-art branching unit for high-voltage drawing-in cables, which is to be mounted to a railroad vehicle or the like, does not have a switching function. In a case of the branching unit without the switching function, a crew is required to manually disconnect a circuit when a ground fault occurs to any of the high-voltage drawing-in cables. This needs a lot of labor. As an improvement measure, for example, there is described a branching unit having the switching function in Patent Literature 1.
The switching device includes a power collector, a circuit breaker unit, and a plurality of power cables. The power collector collects power from an overhead line. The circuit breaker unit is connected to the power collector and installed on a roof of a vehicle. The plurality of power cables are connected to the circuit breaker unit. The circuit breaker unit includes a circuit breaker and branching joints. The circuit breaker is arranged on the roof and is connected to the power collector. The branching joints are arranged under the circuit breaker while being integrally connected to terminal portions of the circuit breaker. The plurality of power cables are connected to the branching joints. In such configuration, the branching joints have eight bushings. A high-voltage cable having a T-shaped cable head is connected to each of four bushings among the eight bushings.